The use of printed circuit boards is mushrooming and significant improvements have been made in the procedures for creating the actual layouts for the printed circuits. For example, computer software packages are available, for CAD systems and personal computers, so that a circuit designer can input schematic circuit designs and general parameters (such as board size and lead thickness). In response to this input data the computer generates an efficient circuit board pattern, for the given parameters, and stores it, e.g. on magnetic media.
At this stage, however, the typical fabrication procedure often involves undesirable delays and costs. For example involves undesirable delays and costs. For example, the stored data, representing the computer designed circuit pattern, is forwarded to a different in-house group, or outside vendor, where it assumes its position in queue, to be converted to master artwork for subsequent photofabrication. After the required masks have been produced, they are forwarded to yet another group, often a separate vendor, to again queue for the actual board fabrication process. This final stage involves exposing the masks to form a photoresist pattern on a continuous metal layer, which is then etched to leave the metal layer pattern of the circuit. The residual photoresist mask is removed and the prototype circuit board is returned to the design originator so that it can be tried in tis intended system. If system problems arise, e.g. because of unforeseen problems with the original schematic circuit design, the entire sequence is begun again.
It will be appreciated from the foregoing that the development of acceptable printed circuit boards for new products is often a major difficulty encountered in trying to shorten new product development periods. One commercially available product for reducing long lead times for prototype circuits utilizes the output of CAD schematics to control a mechanical milling device to fabricate prototype circuits. However, this system is relatively expensive.